Chrysanthemums are often the object of breeding using mutation as a source of variability. This method often results in the formation of periclinal chimeras, which propagated in vitro may be subjected to the separation of components. Therefore it is important to describe effective procedures to determine whether the cultivar is a chimera. The aim of experiments was to describe the method for regeneration of callus and somatic embryos from the root explants of the three chrysanthemum cultivars. In order to investigate the impact of the medium for the callus and somatic embryos formation, in the first experiment root explants included apex were collected and cultured horizontally on the media containing 2 mg∙dm-3 6-benzylaminopurine (BAP) and a 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 mg∙dm-3 2,4-dichlorophenoxyacetic acid (2,4-D). After 10 weeks weight of callus and number of somatic embryos were determined. In the second experiment, callus were cultured on medium with 0.1 and 2 mg∙dm-3 BAP, next after 10 weeks callus was transferred on the three media, which differed content of BAP (0.6, 3.0 and 0.0 mg∙dm-3), kinetin (KIN) (0.0 or 3.0 mg∙dm-3) and 3-indoleacetic acid (IAA) (2.0 or 0.5 mg∙dm-3), as well as thiamin (0.1 or 0.4 mg∙dm-3) and sucrose (30 or 10 g∙dm-3). After 12 weeks the increase of the fresh weight of callus and number of somatic embryos were determined. In the first experiment callus and somatic embryos regeneration was obtained only on media containing auxin and cytokinin. In the second experiment the callus formation was stimulated the best on the medium containing 0.6 mg-dm-3 BAP and 2.0 mg-dm-3 IAA with a standard concentration of sucrose and thiamine, and on the medium enriched with 3.0 mg-dm-3 KIN and 0.5 mg-dm-3 IAA at a reduced sucrose and increased thiamine content. Also a single somatic embryos were regenerated, however, any formation of adventitious shoots was observed. Experiments have demonstrated that induction of the regeneration of the callus and somatic embryos on the root explants of the examined chrysanthemum cultivars was conditioned by the presence the auxin 2,4-D and cytokinin BAP in the medium. Depending on the medium used was obtained to 0.92 somatic embryos per explant. Chrysanthemum root explants can be useful material for the callus and somatic embryos regeneration, however, the description of efficient procedures requires further research.

Jerzy M., Zalewska M., Tymoszuk A., 2013. Effect of kinetin on the elongation of adventitious shoots regenerated in vitro from ligulate florets in Chrysanthemum x grandiflorum /Ra-mat./ Kitam. Book of Abstracts. 8 111 IVCHB International Symposium on In Vitro Culture and Horticultural Breeding. June 2-7, University of Coimbra, Portugal, 89.